Parenteral Nutrition Support for Adults
Manual of Clinical Nutrition Management B- 56 Copyright © 2013 Compass Group, Inc.
cCheck hemoglobin A1C every 6 months.Adapted from the following source with permission from ASPEN. ASPEN does not endorse the use of this material in any form other
than its entirety:
Clark SF. Vitamins and trace elements. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring,
Md: American Society of Enteral and Parenteral Nutrition; 2012:142 (Table 8-6).Parenteral Electrolytes and Requirements
Therapeutic amounts of electrolytes are added to parenteral formulations depending on the patient’s
requirements (11). The serum phosphate levels of critically ill patients should be monitored closely, and
phosphate should be provided when needed due to its essential role in optimal pulmonary function (6).
Electrolytes are available in salt forms, including sodium and potassium as chloride acetate or phosphate;
calcium as chloride, gluconate, or gluceptate; and magnesium as sulfate or chloride. Calcium gluconate and
magnesium sulfate are the preferred forms of these cations because they produce fewer physiochemical
incompatibilities (11). The standard daily electrolyte ranges for adults (Table B-6) should be adjusted as
indicated by the clinical situation (11). Acetate and chloride do not have specific ranges for intake; rather, they
are adjusted as needed to maintain the acid-base balance (10,11).
Table B-6: Daily Electrolyte Requirements (11)
Electrolyte Requirement
Sodium and potassium 1 - 2 mEq/kg + replacement losses
Calcium 10 - 15 mEq
Magnesium 8 - 20 mEq
Phosphate 20 - 40 mmolTotal Nutrient Admixture Parenteral Solutions
Total nutrient admixture parenteral solutions, also known as three-in-one or all-in-one solutions, are
composed of amino acids, dextrose, lipids, vitamins, trace elements, and electrolytes in one container. This
method of nutrient delivery differs from the conventional method (two-in-one) of providing CPN, in which
lipids are in a separate container and “piggybacked in” with the amino acid–dextrose solution. Both types of
parenteral formulation systems are in use today (11). By definition, the total nutrient admixture includes the
lipid emulsion on a daily basis, providing an additional energy source (11). Total nutrient admixtures have
decreased the cost of CPN due to the decreased administrative and equipment costs associated with CPN
preparation decreased nursing time (39). Total nutrient admixtures may also help prevent excessive dextrose
administration in critically ill patients (39,41). Also, lipids are administered over a 24-hour period, which may
promote better patient tolerance (41).
One disadvantage of total nutrient admixtures is that they provide a higher bacterial growth medium than
the conventional system. Also, most particulate matter in the admixture cannot be visually inspected (39,41,42).
Conventional solutions use a 0.22-m in-line filter; however, total nutrient admixtures require a larger in-line
filter (1.2 m) because they contain lipids. This larger filter is sufficient for trapping solution particulates,
precipitates, and Candida albicans, but it does not protect against contaminates such as Staphylococcus
epidermidis, Escherichia coli, and bacterial endotoxins (11,39,41,42). Refer to the previous discussion on lipid
sources for hang-time and infusion guidelines.
Stability and Compatibility
The concentrations of calcium and phosphate ions are directly related to the risk of precipitation, which can
result in serious injury and death (43). As the concentration of either micronutrient rises, the likelihood of
precipitation increases (11). The verification of large calcium doses (more than two times the Dietary
Reference Intake) can help minimize the risk of precipitation (11). The salt form of calcium added to the PN
formulation can have a dramatic impact on the risk of precipitation (11). Calcium gluconate and calcium
gluceptate are generally less dissociated salt forms of calcium than the chloride salts (11). As a result, the
amount of free calcium available to form insoluble complexes with phosphate is reduced (11).